Which of the following methods is NOT suitable for concentrating a protein solution?

How many g of ${\rm{KMn}}{{\rm{O}}_4}$ are needed to prepare 3.75 litre of 0.850 $N$ solution if ${\rm{KMn}}{{\rm{O}}_4}$ is reduced as, ${\rm{MnO}}_4^ - + 8{{\rm{H}}^ + } + 5{\rm{e}} o {\rm{M}}{{\rm{n}}^{2 + }} + 4{{\rm{H}}_2}{\rm{O}}$

A metal M forms a volatile carbonyl complex $M(CO)_x$. 0.525g of this complex is heated in a closed vessel of volume 250 mL at $50^\circ C$. The pressure inside the vessel after complete decomposition of the complex is 746 Torr. If the gas constant R is 0.0821 L atm $K^{-1} mol^{-1}$, what is the value of x in the formula $M(CO)_x$? (Assume the metal M does not contribute significantly to the pressure)

What weight of ${\rm{HN}}{{\rm{O}}_3}$ is needed to convert 5 g of iodine into iodic acid according to the reaction, ${{\rm{I}}_2} + {\rm{HN}}{{\rm{O}}_3} o {\rm{HI}}{{\rm{O}}_3} + {\rm{N}}{{\rm{O}}_2} + {{\rm{H}}_2}{\rm{O}}?$ ?

What is the normality of a ${\rm{KMn}}{{\rm{O}}_4}$ solution to be used as an oxidant in acid medium, which contain 15.8 g of the compound in 100 mL of solution? Mol. wt. of ${\rm{KMn}}{{\rm{O}}_4}$ is 158 :

What weight of ${\rm{HN}}{{\rm{O}}_3}$ is needed to convert 5 g of iodine into iodic acid according to the reaction, ${{\rm{I}}_2} + {\rm{HN}}{{\rm{O}}_3} o {\rm{HI}}{{\rm{O}}_3} + {\rm{N}}{{\rm{O}}_2} + {{\rm{H}}_2}{\rm{O}}?$ ?

What weight of ${\rm{HN}}{{\rm{O}}_3}$ is needed to convert $5\,g\,{I_2}$  into ${\rm{HI}}{{\rm{O}}_3},{\rm{HN}}{{\rm{O}}_3} o {\rm{NO}}?$

1 gram of sodium hydroxide was reacted with $25 \mathrm{mL}$ of $0.75 \mathrm{M}$ sulfuric acid ($\mathrm{H_2SO_4}$). What mass of sodium hydroxide remains unreacted?

What is the molarity of a solution containing 1 mole of solute in 500 mL of solution?

For the reaction : ${{\rm{N}}_2} + 3{{\rm{H}}_2} o 2{\rm{N}}{{\rm{H}}_3}$ ; if ${E_1}\,and\,{E_2}$ are equivalent masses of $N{H_3}$ and ${N_2}$ respectively, then ${E_1}\, - \,{E_2}$ is :

In the following change, $3{\rm{Fe}} + 4{{\rm{H}}_2}{\rm{O}} o {\rm{F}}{{\rm{e}}_3}{{\rm{O}}_4} + 4{{\rm{H}}_2}$. If the atomic weight of iron is 56, then its equivalent weight will be :